Smart cloud workload balancer

ABSTRACT

A method and system. A cloud computing system is configured into an operative status by defining a virtual machine (VM) topology representing a respective virtual machine assignment for each physical server of the cloud computing system. An objects database (ODB) stores: a respective software cost per software application in one or more software license pools, and a power cost of the cloud computing system. It is determined that the cloud computing system does not perform optimally with respect to a total cost of the cloud computing system, which is a sum of the respective software cost and the power cost. The workload of the cloud computing system is distributed pursuant to a new VM topology that has a minimum total cost of the cloud computing system.

This application is a continuation application claiming priority to Ser.No. 14/531,068, filed Nov. 3, 2014, which is a continuation of Ser. No.13/204,858, filed Aug. 8, 2011, U.S. Pat. No. 8,909,785, issued Dec. 9,2014.

BACKGROUND

The present invention discloses a system and associated method fordynamically optimizing workload distribution in a cloud computing systembased on operating cost. Conventional workload optimization methods incloud computing systems use static planning for overall operation. Sincesoftware licenses are required to run software application programs thatservices clients of the cloud computing system, statically planning thenumber of software licenses in the cloud computing system causesoperating cost issues. When the cloud computing system acquires enoughnumber of software licenses to fully utilize all physical servers at alltime, the cloud computing system incurs unnecessary additional softwarelicense cost. Having too few number of software licenses to reduce extracost may degrade utilization of the physical servers and performance ofthe cloud computing system.

BRIEF SUMMARY

According to one embodiment of the present invention, a method fordynamically optimizing workload of a cloud computing system comprises:configuring, by a smart cloud workload balancer (SCWB), the cloudcomputing system into an operative status by defining a virtual machine(VM) topology representing a respective virtual machine assignment foreach physical server of the cloud computing system such that the cloudcomputing system services workload of the cloud computing system by useof the VM topology, wherein the cloud computing system comprises anobjects database (ODB) storing system configuration parameters of:business policies, zero or more physical server availability zones, zeroor more physical server restriction zones, zero or more physical serverlocation pools, zero or more software license pools, a respectiveavailable licenses per software application in the software licensepools, a respective software cost per said software application, a powercost of the cloud computing system, at least one virtual machine (VM),and zero or more installed licenses per VM; determining that the cloudcomputing system does not perform optimally with respect to a total costof the cloud computing system based on the system configurationparameters stored in the ODB, wherein said total cost is a sum of therespective software cost and the power cost; and redistributing workloadof the cloud computing system pursuant to a new VM topology that has aminimum total cost of the cloud computing system pursuant to saidbusiness policies stored in the ODB.

According to one embodiment of the present invention, a computer programproduct comprises a computer readable memory unit that embodies acomputer readable program code. The computer readable program codecontains instructions that, when run by a processor of a computersystem, implement a method for dynamically optimizing workload of acloud computing system.

According to one embodiment of the present invention, a computer systemcomprises a processor, a memory coupled to the processor, and a computerreadable storage device coupled to the processor, said storage devicecontaining program code configured to be executed by the processor viathe memory to implement a method for dynamically optimizing workload ofa cloud computing system.

According to one embodiment of the present invention, a process forsupporting computer infrastructure, said process comprising providing atleast one support service for at least one of creating, integrating,hosting, maintaining, and deploying computer-readable code in acomputing system, wherein the code in combination with the computingsystem is capable of performing a method for dynamically optimizingworkload of a cloud computing system.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates a cloud computing system for optimizing workload bydynamically reallocating virtual machines of the cloud computing system,in accordance with embodiments of the present invention.

FIG. 2 illustrates functional components of the smart cloud workloadbalancer (SCWB) in the cloud computing system of FIG. 1, in accordancewith the embodiments of the present invention.

FIG. 3 is a flowchart depicting a method for optimizing workload bydynamically reallocating virtual machines of the cloud computing system,which is performed by the smart cloud workload balancer (SCWB) 13 ofFIG. 1, in accordance with the embodiments of the present invention.

FIG. 4 is a flowchart depicting system configuration substeps performedin place of step 100 of FIG. 3 by the system configuration module of thesmart cloud workload balancer (SCWB), in accordance with the embodimentsof the present invention.

FIG. 5 is a flowchart depicting monitoring substeps performed in placeof step 200 of FIG. 3 by the monitoring and control module (MC) of thesmart cloud workload balancer (SCWB), in accordance with the embodimentsof the present invention.

FIG. 6 is a flowchart depicting maintenance substeps performed in placeof step 300 of FIG. 3 by the maintenance module of the smart cloudworkload balancer (SCWB) in accordance with the embodiments of thepresent invention.

FIG. 7A is a flowchart depicting optimization substeps performed inplace of step 400 of FIG. 3 by the workload optimizer (WO) of the smartcloud workload balancer (SCWB) in accordance with the embodiments of thepresent invention.

FIG. 7B is a flowchart depicting cost minimization substeps performed inplace of step 420 of FIG. 7A by the workload optimizer (WO) of the smartcloud workload balancer (SCWB), in accordance with the embodiments ofthe present invention.

FIG. 8 is a flowchart depicting reporting substeps performed in place ofstep 500 of FIG. 3 by the smart cloud workload balancer (SCWB) inaccordance with the embodiments of the present invention.

FIG. 9 illustrates a computer system used for optimally balancingworkload among at least two physical servers of the cloud computingsystem, in accordance with the embodiments of the present invention.

DETAILED DESCRIPTION

FIG. 1 illustrates a cloud computing system 10 for optimizing workloadby dynamically reallocating virtual machines of the cloud computingsystem 10, in accordance with embodiments of the present invention.

The cloud computing system 10 comprises an administrator 11, aconfiguration management database (CMDB) 12, a smart cloud workloadbalancer (SCWB) 13, an asset management database (AMDB) 16, a virtualmachine and hardware manager (VMM) 17, and at least two physicalservers. The CMDB 12, the SCWB 13, the AMDB 16, and the VMM 17 run on arespective generic computer system. See descriptions of FIG. 9 infra fordetails of a generic computer system. An example of the cloud computingsystem 10 is IBM® Global Technology Services (GTS) infrastructure sharedamong customers of the IBM GTS, which provides data processing servicesby use of System x physical servers virtualized by VMware®, and System pphysical servers virtualized by PowerVM. (IBM is a registered trademarkof International Business Machines Corporation in the United States andother countries; VMware is a registered trademark of VMware, Inc. in theUnited States and other countries.)

The administrator 11 is a human user configuring and monitoringoperations of the cloud computing system 10 by interacting with the SCWB13. The administrator 11 sets policies controlling the workloadbalancing, defines costs for operating the cloud computing system 10 asa sum of electrical power usage and software licensing fees, verifies anensemble status as to virtual machine assignment for respective physicalservers, and creates, deletes, and reconfigures virtual machines inrespective physical servers. The administrator 11 also receives aperformance report in response to a request for the performance report.

The smart cloud workload balancer (SCWB) 13 performs automated workloadoptimization over virtual machines of the cloud computing system 10 suchthat the cloud computing system 10 performs given workload with aminimum cost. The SCWB 13 distributes the workload over the virtualmachines in a way to minimize the operational costs of the cloudcomputing system 10 based on technical, availability and softwarelicense constraints of the cloud computing system 10. Examples ofconventional workload balancing methods in cloud computing systems maybe, inter alia, the VMware Distributed Resource Scheduling, the Citrix®Dynamic Workload Balancing, the IBM Systems Director VMControl, etc.(Citrix is a registered trademark of Citrix Systems, Inc. and itsaffiliates in the United States and other countries.) The SCWB 13automatically reconfigures workload of the cloud computing system 10among virtual machines by utilizing dynamic zoning of physical serversbased on policy restriction zones and availability zones for workloadbalancing and by utilizing multiple sources of performance data, a costmodel for software license cost, and an automated workload optimizingmethod based on the performance data and the cost model. In thisspecification, the term “physical servers availability zone” is definedas a logical group of physical servers that shares one or more externalphysical components such as power distribution units, datacenter room,rack, network switches, external storage, etc., such that all physicalservers in one availability zone operate atomically but not partiallyavailable. Also in this specification, the term “physical serversrestriction zone” is defined as a dynamic logical group of physicalservers within a specific physical server availability zone thatrepresents a logical condition such as, inter alia, a group havinglicense to run a specific software program during a specific timeperiod. See description of FIG. 2, infra, for functional components ofthe SCWB 13. See description of FIG. 3, infra, for steps performed bythe SCWB 13.

The configuration management database (CMDB) 12 stores information aboutdependencies between said at least one physical server and virtualmachines running on respective physical servers and topology informationas to virtual machine assignment for respective physical servers. TheSCWB 13 updates the CMDB 12 with new topology information resulting fromoptimization of workload distribution among physical servers. In thisspecification, terms “VM topology” and “topology information” are usedinterchangeably.

In another embodiment of the present invention, the cloud computingsystem 10 further comprises an external integration tool and/or anexternal cloud automation tool. The external integration tool extendsthe functions of the SCWB 13 by exchanging various data and metadatasuch as, inter alia, user directories, billing and accounting data,change management data, service request, etc. The external integrationtool interacts with specific components within the SCWB 13. Seedescription of FIG. 2 infra for details of the components interfacingthe external integration tool.

In the same embodiment, the external cloud automation tool receives enduser requests and automates provisioning of services in the cloudcomputing system 10. Examples of the external cloud automation tool maybe, inter alia, ITSAM®, Eucalyptus™, etc. (ITSAM is a registeredtrademark of Expetec Corporation in the United States and/or othercountries; Eucalyptus is a trademark of Eucalyptus Systems, Inc., in theUnited States and/or other countries.)

The asset management database (AMDB) 16 stores software assetinformation regarding a number of available software licenses, a numberof installed software licenses, etc. In one embodiment of the presentinvention, the administrator 16 provides the asset information of theAMDB 16 by interactive input to the SCWB 13, wherein the assetinformation is not stored in the AMDB 16.

The virtual machine and hardware manager (VMM) 17 monitors and managessaid at least two physical servers and virtual machines running on saidphysical servers. The SCWB 13 interacts with the VMM 17 in receivingperformance data of the cloud computing system 10 and electrical powerusage information. The SCWB 13 automatically controls VM allocation overphysical servers by use of the VMM 17, communicating via, inter alia,hypervisors, VMM application programming interfaces (APIs). The VMM 17receives requests for virtual operations and physical operations fromthe SCWB 13 and performs adding, moving, deleting, suspending virtualmachines to and from respective physical machines, changingconfiguration of virtual machine assignment for respective physicalservers. Examples of the VMM 17 may be, inter alia, the HardwareManagement Console (HMC), the VMware vCenter, the Citrix XenCenter, theIBM System Director, etc.

A physical server 18 of said at least two physical servers is a genericcomputer system that runs zero or more virtual machines. A virtualmachine (VM) 19 of said zero or more virtual machines is a softwareimplementation of a computer system that services a portion of workloadof the cloud computing system 10. In servicing the workload, the virtualmachine 19 runs various software applications, which is associated witha respective software license cost. Overall software license cost ofrunning the software applications in the cloud computing system 10 iscalculated based on a respective number of physical or virtual centralprocessing units (CPUs) in each physical server where a virtual machinethat performs a software application is running. In this specification,the terms CPU and processor are used interchangeably.

FIG. 2 illustrates functional components of the smart cloud workloadbalancer (SCWB) 13 in the cloud computing system 10 of FIG. 1 supra, inaccordance with the embodiments of the present invention.

The SCWB 13 comprises an objects database (ODB) 21, a workload optimizer(WO) 22, a monitoring and control module (MC) 23, a user interface (UI)24, an automated operations application programming interface (AO-API)25, a bulk data loader interface (BDLI) 26, and an automation dispatcherinterface (ADI) 27.

The objects database (ODB) 21 stores information necessary for workloadoptimization over virtual machines (VMs) running on physical servers ofthe cloud computing system as used by the workload optimizer (WO) 22.The information is gathered from various components of the cloudcomputing system 10 of FIG. 1 supra. In one embodiment of the presentinvention, the information stored in the ODB 21 comprises policyinformation, monitoring information, configuration data and asset data.

The policy information indicates various policy data items stored in theODB, which define workload balancing policies per inputs provided by theadministrator of the cloud computing system. Examples of the policy dataitems may be, inter alia, software asset information regarding a numberof available software licenses and a number of installed softwarelicenses as buffered from the AMDB 16 of FIG. 1 supra, thresholds ofworkload per VM and/or physical server, a range of VM relocationfrequency permitted in the cloud computing system, a level of complianceto the software license agreement, software license restrictions, VMbusiness priorities, physical servers restriction zones and physicalservers availability zones, physical servers location pools, VM affinityrules and VM anti-affinity rules, hardware constrains and powerconsumption limits, etc. In this specification, the term “physicalservers location pool” is defined as a logical group of physical servershosted by a same data center or a network such that the SCWB prevents anetwork congestion that may result from high data traffic requiredbetween virtual machines running in remote locations by allocating twovirtual machines having high communication requirements in a samephysical servers location pool. In this specification, the term “VMaffinity rule” is defined as a relationship between two virtual machinesthat perform better when the two VMs run in a same physical server. Inthis specification, the term “VM anti-affinity rule” is defined as arelationship between two virtual machines that cannot perform in a samephysical server.

The monitoring information indicates various monitoring data itemsstored in the ODB as collected from the physical servers of the cloudcomputing system while normal operation processing the workload.Examples of the monitoring data items may be, inter alia, respectiveelectrical power consumption of each physical server, resourceutilization information for each physical server and VM, wherein theresource comprises processor, memory, and input/output (I/O) datacommunication channel bandwidth, etc.

The configuration information indicates various configuration data itemsstored in the ODB as configured by the administrator and as bufferedfrom the CMDB 12 of FIG. 1 supra. Examples of the configuration dataitems may be, inter alia, virtual machine (VM) configuration andphysical server configuration. The VM configuration specifies, for eachVM, a respective capacity and target performance level for resources ofeach VM, comprising virtual processors, memory, and network. Thephysical server configuration specifies, for each physical server, arespective number of core processors, a respective amount of memory, CPUperformance level relative to other CPU types available in the otherphysical servers in the cloud computing system, etc.

The workload optimizer (WO) 22 automatically performs workloadoptimization by use of linear or quadratic programming based oninformation retrieved from the ODB 21 such that the WO 22 dynamicallydecides a optimal workload distribution for virtual machines running inthe physical servers of the cloud computing system, wherein the workloaddistribution improves performance of the cloud computing system as wellas meets operation criteria of the cloud computing system as specifiedby the information from the ODB 21. See description of step 400 of FIG.3 infra and FIGS. 7A-7B infra for detailed operations of the WO 22.

The monitoring and control module (MC) 23 monitors virtual machines andphysical servers of the cloud computing system for hardware constraintsand system availability data during normal business operation. Seedescription of step 200 of FIG. 3 infra and FIG. 5 infra for detailedoperations of the MC 23.

The user interface (UI) 24 enables the administrator of the cloudcomputing system to interact with the SCWB 13 by providing inputsdetermining restriction policies and other system configurationinformation. See description of steps 100 and 500 of FIG. 3 infra fordetailed operations of the UI 24.

The automated operations application programming interface (AO-API) 25is an application programming interface (API) used by the external cloudautomation tool and/or the external integration tool to interact withthe SCWB for system services provided by other components of the cloudcomputing system 10 of FIG. 1 supra. Examples of the system services maybe, inter alia, creating a new virtual machine in a physical server,delete an existing virtual machine from a physical server, etc. Seedescription of step 100 of FIG. 3 infra for detailed operations of theAO-API 25.

The bulk data loader interface (BDLI) 26 enables database components ofthe cloud computing system 10 to update the content of the ODB 21. Theexternal integration tool interacts with a bulk data loader interface(BDLI) 26 for data synchronization. See description of step 100 of FIG.3 infra for detailed operations of the BDLI 26.

The automation dispatcher interface (ADI) 27 enables the virtual machineand hardware manager (VMM) 17 of FIG. 1 supra to interact with the SCWB13 in provisioning, changing, and removing virtual machines, inprovisioning a new physical server, and in shutting down an existingphysical server. See description of step 400 of FIG. 3 infra fordetailed operations of the ADI 27.

The SCWB 13 of the present invention dynamically optimizes workloaddistribution of virtual machines (VMs) over physical servers in thecloud computing system such that performing the workload in pursuant toan optimized workload distribution minimizes software license cost ofthe cloud computing system. To optimize workload distribution, the SCWB13 takes system information into account in building a software licensecost model. See description of the ODB 21 for examples of the systeminformation. The software license cost model may differ based onlicensing objectives such as licensing per physical machines, licensingper processors, licensing per cores, licensing by sub-capacitydifferentiation of software costs by processor type, etc. In oneembodiment of the present invention, the software license cost iscalculated based on a number of VMs running a software applicationsubject to a respective software license agreement. The SCWB 13dynamically analyzes the software license cost model and calculates atotal cost of cloud computing and generates a new VM topology withminimum total cost subject real-time content of the ODB 21, as describedin FIGS. 7A and 7B infra. The SCWB 13 controls management of the cloudcomputing system, virtual machine assignment and applicationdistribution, interfaces with external data sources and processingcomponents, etc.

Conventional workload optimization methods that use static planning foroptimization are either ineffective or expensive. The cloud computingsystem needs to acquire software licenses for all physical servers in aresource pool to run a specific software application. Including allphysical servers in the resource pool is not cost effective in terms ofthe software license cost since not all physical servers need to run thesoftware application at all time. To reduce the software license cost,the cloud computing system may limit a number of physical servers in theresource pool by excluding certain physical servers from the resourcepool, which limits flexible virtual machine reallocation of the cloudcomputing system because virtual machines running the softwareapplication cannot be allocated on the physical servers that is excludedfrom the resource pool. In contrast, the workload optimization of thepresent invention dynamically reallocates any virtual machine to anyphysical server, which provides flexible and cost-effective workloadoptimization.

FIG. 3 is a flowchart depicting a method for optimizing workload bydynamically reallocating virtual machines of the cloud computing system10 of FIG. 1 supra, which is performed by the smart cloud workloadbalancer (SCWB) 13 of FIG. 1, supra, in accordance with the embodimentsof the present invention.

In step 100, the SCWB configures the cloud computing system forproduction/normal operation by use of a first group of functional blockscomprising the user interface (UI) 24, automated operations applicationprogramming interface (AO-API) 25, and the bulk data loader interface(BDLI) 26 of FIG. 2 supra. In this specification, the first group offunctional blocks in the SCWB is referred to as a system configurationmodule. See description of FIG. 4, infra, for details of steps performedby the system configuration module for system configuration. After step100 is completed, the cloud computing system starts production/normaloperation, and the SCWB performs steps 200, 300, 400 and 500,concurrently with the production/normal operation, which arerespectively associated with either a human trigger provided by theadministrator or an automatic trigger given by the cloud computingsystem.

In step 200, the SCWB monitors performance of the cloud computing systemby use of the monitoring and control module (MC) 23 of FIG. 2 supra, andupdates content of the ODB with the monitored performance data. Seedescription of FIG. 5, infra, for details of steps performed by the MCfor monitoring performance of the cloud computing system.

In step 300, the SCWB performs maintenance operations for the cloudcomputing system by use of a second group of functional blockscomprising the monitoring and control module (MC) 23 and the automationdispatcher interface (ADI) 27 of FIG. 2 supra. In this specification,the second group of functional blocks in the SCWB is referred to as amaintenance module. See description of FIG. 6, infra, for details ofsteps performed by the maintenance module for maintenance of the cloudcomputing system.

In step 400, the SCWB optimizes workload of virtual machines within thecloud computing system by use of the workload optimizer (WO) 22 of FIG.2 supra. See description of FIG. 7A, infra, for details of stepsperformed for workload optimization.

In step 500, the SCWB reports performance of the cloud computing systembased on user request by use of the UI 24 of FIG. 2 supra. Seedescription of FIG. 8, infra, for details of steps performed forreporting of the cloud computing system.

FIG. 4 is a flowchart depicting system configuration substeps performedin place of step 100 of FIG. 3 supra by the system configuration moduleof the smart cloud workload balancer (SCWB), in accordance with theembodiments of the present invention.

In step 110, the system configuration module identifies virtual machineand hardware manager (VMM) and physical servers of the cloud computingsystem according to inputs provided by the administrator. The systemconfiguration module subsequently updates data items corresponding tothe VMM and physical servers stored in the object database (ODB). Thenthe system configuration module proceeds with step 120.

In step 120, the system configuration module defines business policiesof the cloud computing system according to inputs provided by theadministrator and updates data items corresponding to the businesspolicies of the ODB. Examples of business policies may be, inter alia,thresholds of virtual machine move frequency, etc. Then the systemconfiguration module proceeds with step 130.

In step 130, the system configuration module defines physical serveravailability zones, physical servers restriction zones, and physicalservers location pools according to inputs provided by the administratorand updates respective data items corresponding to the physical serveravailability zones, physical servers restriction zones, and physicalservers location pools of the ODB. Each physical server in the cloudcomputing system participates in one availability zone and at least onerestriction zone. Allocating a virtual machine in a physical serverincluded in a restriction zone of said at least one restriction zone isdynamically managed by the SCWB. Each software license constraint isimplemented as a respective restrict zone. Multiple restriction zonesmay exist within a single availability zone. Then the systemconfiguration module proceeds with step 140.

In step 140, the system configuration module creates software licensepools, and respectively defines available licenses and software licensecost for each software application within the software license poolsaccording to inputs provided by the administrator. The systemconfiguration module subsequently updates data items respectivelycorresponding to the created software license pools, defined availablelicenses and software license cost as stored in the object database(ODB). Then the system configuration module proceeds with step 150.

In step 150, the system configuration module defines power cost of thecloud computing system according to inputs provided by theadministrator, which is defined as a sum of respective electrical powercost for all physical servers of the cloud computing system. The systemconfiguration module subsequently updates a data item corresponding tothe defined power cost in the ODB. Then the system configuration moduleproceeds with step 160.

In step 160, the system configuration module defines and identifiesvirtual machines (VM) of the cloud computing system according to inputsprovided by the administrator. The system configuration modulesubsequently updates data items respectively corresponding to each VM inthe ODB. Then the system configuration module proceeds with step 170.

In step 170, the system configuration module defines installed licensesper virtual machine (VM) according to inputs provided by theadministrator. The system configuration module subsequently updates dataitems respectively corresponding to installed license number for each VMin the ODB. Then the system configuration module proceeds with step 180.

In step 180, the system configuration module defines a VM topology,which specifies a respective mapping between each VM and an associatedphysical machine in which each VM is running according to inputsprovided by the administrator. The VM topology is also determined by VMaffinity rules and VM anti-affinity rules. The VM affinity rules definegroups of virtual machines that may be allocated in a same physicalserver, and the VM anti-affinity rules define groups of virtual machinesthat should not be allocated in a same physical server. The systemconfiguration module subsequently updates a data item corresponding tothe defined VM topology in the ODB. Then the system configuration moduleterminates as completing system configuration, and the cloud computingsystem starts production/normal operation. The SCWB proceeds with atleast one step selected from steps 200, 300, 400 and 500 according toinputs provided by the administrator.

FIG. 5 is a flowchart depicting monitoring substeps performed in placeof step 200 of FIG. 3 supra by the monitoring and control module (MC) ofthe smart cloud workload balancer (SCWB), in accordance with theembodiments of the present invention.

The MC performs steps 210 through 260 described below for eachmonitoring cycle predetermined by the administrator.

In step 210, the MC collects performance data from virtual machinesand/or physical servers as the virtual machines process workloads of thecloud computing system during the production/normal operation. Then theMC proceeds with step 220.

In step 220, the MC determines whether the cloud computing systemperforms optimally based on the performance data collected in step 210.If the MC determines that the cloud computing system performs optimally,then the MC proceeds with step 230 for further monitoring. If the MCdetermines that the cloud computing system does not perform optimally,then the MC proceeds with step 260. Wherein the performance data fromstep 210 indicates that the cloud computing system reaches a peak usageof any physical server of that there exist a failed physical server, theMC determines that the cloud computing system does not perform optimallyand needs optimization.

In step 230, the MC collects power usage data from each physical serverin the cloud computing system during the production/normal operation.Then the MC proceeds with step 240.

In step 240, the MC monitors real-time availability of the virtualmachines and the physical servers. Then the MC proceeds with step 250.

In step 250, the MC updates objects database (ODB) with data collectedin steps 230 and 240. Then the MC terminates a cycle of monitoring.

In step 260, the MC triggers workload optimization by invoking theworkload optimizer (WO), step 400 of FIG. 3 supra. Then the MCterminates a cycle of monitoring.

FIG. 6 is a flowchart depicting maintenance substeps performed in placeof step 300 of FIG. 3 supra by the maintenance module of the smart cloudworkload balancer (SCWB) in accordance with the embodiments of thepresent invention.

In step 310, the maintenance module changes system/VM configurationparameter values stored in the ODB according to inputs provided by theadministrator. See descriptions of the ODB in FIG. 2 supra for specificdata items comprising the system configuration parameter. Then themanagement module proceeds with step 340.

In step 320, the maintenance module manages physical server according toa physical server management operation provided by the administrator, byinteracting with the virtual machine and hardware manager (VMM) of thecloud computing system. A value of the physical server managementoperation is selected from {add, delete, suspend}, wherein add operationadds a new physical server to a current pool of physical servers andsubsequently marks the added physical server as available for runningvirtual machines, wherein delete operation removes a physical serverfrom the pool and subsequently turns the removed physical server off,and wherein suspend operation temporarily turns off a physical serverand marks the physical server as unavailable for running virtualmachines. The physical server management operations result in updatingthe ODB. Then the management module proceeds with step 340.

In step 330, the maintenance module manages virtual machines (VMs)according to a VM management operation provided by the administrator, byinteracting with the virtual machine and hardware manager (VMM) of thecloud computing system. A value of the VM management operation isselected from {add, delete, suspend}, wherein add operation instantiatesa new virtual machine in a physical server and subsequently marks thenew virtual machine as available for running a software application,wherein delete operation removes a virtual machine from a pool ofvirtual machines, and wherein suspend operation temporarily put avirtual machine in a suspended state such that the virtual machine doesnot consume any resources, neither the software licenses nor physicalresources. The VM management operations result in updating the ODB. Thenthe management module proceeds with step 340.

In step 340, the maintenance module triggers workload optimization byinvoking the workload optimizer (WO). Then the maintenance moduleterminates and the SCWB proceeds with the WO performing step 400 of FIG.3 supra.

FIG. 7A is a flowchart depicting optimization substeps performed inplace of step 400 of FIG. 3 supra by the workload optimizer (WO) of thesmart cloud workload balancer (SCWB) in accordance with the embodimentsof the present invention.

In step 410, the WO retrieves data items necessary for optimization fromthe objects database (ODB). Then the WO proceeds with step 420.

In step 420, the WO determines a new VM topology by calculating minimumtotal cost and minimum number of VM relocation. In one embodiment of thepresent invention, the WO employs two-phase calculation using quadraticprogramming (QP) enabled solvers. See description of FIG. 7B infra forsteps performed in determining the new VM topology. Then the WO proceedswith step 430.

In step 430, the WO turns on physical servers necessary for the new VMtopology as determined in step 420 supra. Then the WO proceeds with step440.

In step 440, the WO relocates virtual machines (VM) among physicalservers pursuant to the new VM topology. Then the WO proceeds with step450.

In step 450, the WO adjusts status information of relocated VMs pursuantto the new VM topology by use of a respective VM management operationselected from {add, delete, suspend}. Then the WO proceeds with step460.

In step 460, the WO turns off physical servers not used for virtualmachines in the new VM topology. Then the WO proceeds with step 470.

In step 470, the WO updates the ODB with data items reflecting the newVM topology. Then the WO terminates a cycle of workload optimization,and the cloud computing system continues workload production pursuant tothe new VM topology.

FIG. 7B is a flowchart depicting cost minimization substeps performed inplace of step 420 of FIG. 7A supra by the workload optimizer (WO) of thesmart cloud workload balancer (SCWB), in accordance with the embodimentsof the present invention.

The workload optimizer (WO) performs steps 4201 and 4202 based on dataretrieved from the object database (ODB) of the SCWB. Step 4201 and step4202 is mathematically modeled by use of mathematical optimizationtechniques such as quadratic programming (QP) and quadraticallyconstrained quadratic program (QCQP), which is implemented by use of aQP and QCQP enabled solver.

In step 4201, the WO minimizes a total cost of cloud computing (TC) forall software running on VMs on each physical servers, as a first phaseof the two-phase VM topology calculation, subject to constraintscomprising: each VM being associated to only one physical server; athreshold limiting the number of physical relocation; the amount ofavailable resources per physical server; affinity and anti-affinity rulefor each pair of two VMs; and amount of software license usage withinlicensed limit. In the first phase of step 4201, the WO discovers aminimum total cost (TC) without limiting a total number of VMrelocations. Then the WO proceeds with step 4202 for a second phase ofthe two-phase VM topology calculation.

The objective function of the total cost (TC), as a sum of software costfor all running software and electrical power cost for all runningphysical servers, is formulated as Formula [A].

Σ_(s)(SC _(s)*Σ_(j)(SU _(s,j) *IS _(s,j)))+Σ_(j)(PC _(j) *B _(j))  [A]

wherein SC_(s) is a respectively predefined unit cost for each software(s), wherein SU_(s,j) is a respectively predefined number of softwareunits required to run s-th software (s) in j-th physical server, whereinIS_(s,j) is a first binary variable that has value one (1) if thereexist a VM that runs s-th software (s) in j-th physical server, and thathas value zero (0) if there is no such VM, wherein PC_(j) is arespective constant describing electrical power cost of j-th physicalserver, and wherein B_(j) is a second binary variable that has value one(1) if j-th physical server is turned on, and that has value zero (0) ifj-th physical server is turned off.

The constraints of the total cost (TC) are formulated as Formulae [B],[C], [D], [E], [F], [G], [H], [I], [J], and [K], respectively, as below.

Formula [B] is a first group of constraints and is defined for each i-thVM.

It indicates that i-th virtual machine (VM) is associated with j-thphysical server, ensuring that each VM is associated with exactly onephysical server within the cloud computing system.

Σ_(j) KVM_(i,j)*VM_(i,j) *B _(j)=1  [B]

wherein KVM_(i,j) is a third binary parameter representing whether ornot j-th physical server enables i-th VM to run that has value one (1)if i-th VM can run on j-th physical server, and that has value zero (0)if i-th VM cannot run on j-th physical server such that a group ofphysical servers having value one (1) for KVM parameter comprise aphysical server availability zone with respect to i-th VM, whereinVM_(i,j) is a fourth binary variable that has value one (1) if i-th VMwill run on j-th physical server after workload optimization, and thathas value zero (0) if i-th VM will not run on j-th physical server afterworkload optimization, and wherein B_(j) is the second binary variablethat has value one (1) if j-th physical server is turned on, and thathas value zero (0) if j-th physical server is turned off as defined inFormula [A] supra.

Formula [C] is a second group of constraints that is defined respectiveto i-th VM, which represents a predefined threshold for a number ofphysical server relocation in one optimization cycle.

RVM_(i)+(1−Σ_(j)(CVM_(i,j)*VM_(i,j)))≦MRVM_(i)  [C]

wherein RVM_(i) is a parameter representing a number of relocations i-thVM had gone through in current optimization cycle, wherein CVM_(i,j) isa binary parameter that has value one (1) if i-th VM currently runs onj-th physical server, and that has value zero (0) if i-th VM does notcurrently run on j-th physical server, wherein VM_(i,j) is the fourthbinary variable that has value one (1) if i-th VM will run on j-thphysical server after workload optimization, and that has value zero (0)if i-th VM will not run on j-th physical server after workloadoptimization, as defined in Formula [B] supra, and wherein MRVM_(i) is apredefined maximum number of relocations allowed for i-th VM in acurrent optimization cycle.

Formula [D] is a third group of constraints defined for a respectivephysical server to ensure amount of memory in the respective physicalserver is sufficient to run all virtual machines assigned to therespective physical server after optimization.

Σ_(i)(VM_(i,j) *M _(i))≦BM _(j)  [D]

wherein VM_(i,j) is the fourth binary variable that has value one (1) ifi-th VM will run on j-th physical server after workload optimization,and that has value zero (0) if i-th VM will not run on j-th physicalserver after workload optimization as defined in Formula [B] supra,wherein M_(i) indicates amount of memory required for i-th VM, andwherein BM_(j) indicates maximum amount of memory usable in j-thphysical server.

Formula [E] is a fourth group of constraints defined for a respectivephysical server to ensure a number of CPU in the respective physicalserver is sufficient to run all virtual machines assigned to therespective physical server after optimization.

Σ_(i)(VM_(i,j) *C _(i))≦BC _(j)  [E]

wherein VM_(i,j) is the binary variable that has value one (1) if i-thVM will run on j-th physical server after workload optimization, andthat has value zero (0) if i-th VM will not run on j-th physical serverafter workload optimization as defined in Formula [B] supra, whereinC_(i) indicates an amount of CPU capacity/processing power required fori-th VM running in j-th physical server, and wherein BC_(j) indicates amaximum amount of CPU capacity/processing power usable in j-th physicalserver.

Formula [F] is a fifth group of constraints defined for a respectivephysical server to ensure input/output (I/O) capacity in the respectivephysical server is sufficient to run all virtual machines assigned tothe respective physical server after optimization.

Σ_(i)(VM_(i,j) *IO _(i))≦BIO _(j)  [F]

wherein VM_(i,j) is the fourth binary variable that has value one (1) ifi-th VM will run on j-th physical server after workload optimization,and that has value zero (0) if i-th VM will not run on j-th physicalserver after workload optimization as defined in Formula [B] supra,wherein IO_(i) indicates a respective I/O capacity required for i-th VMrunning in j-th physical server, and wherein BIO_(j) indicates maximumI/O capacity usable in j-th physical server.

Formula [G] is a sixth group of constraints, defined for each pair ofvirtual machines that have predefined affinity rules stored in the ODB,to force that said pair of two virtual machines (VM_(a) and VM_(b))having the predefined affinity rules run in a same physical server.

Σ_(j)(VM_(a,j)*VM_(b,j))=1  [G]

wherein VM_(a,j) indicates a first virtual machine (VM_(a)) running onj-th physical server, and VM_(b,j) indicates a second virtual machine(VM_(b)) running on j-th physical server as defined in Formula [B]supra.

Formula [H] is a seventh group of constraints, defined for each pair ofvirtual machines that have predefined anti-affinity rules stored in theODB, to avoid that said each pair of virtual machines having thepredefined anti-affinity rules run in a same physical server.

Σ_(j)(VM_(a,j)*VM_(b,j))=0  [H]

wherein VM_(a,j) indicates the first virtual machine (VM_(a)) running onj-th physical server, and VM_(b,j) indicates the second virtual machine(VM_(b)) running on j-th physical server, as defined in Formula [B]supra.

Formulae [I], [J] and [K] are an eighth group of constraints defined foreach software to ensure that software licenses are used in compliancewith a software license policy respectively associated with eachsoftware application.

Σ_(j)(IS _(s,j) *SU _(s,j))≦L _(s)*(1+LCP _(s))  [I]

Σ_(i)(VM_(i,j) *SVM_(i,s))≦BigK*IS _(s,j)  [J]

IS _(s,j)≦Σ_(i)(VM_(i,j) *SVM_(i,s))  [K]

wherein IS_(s,j) the first binary variable that has value one (1) ifthere exist a VM that runs s-th software (s) in j-th physical server,and that has value zero (0) if there is no such VM, as defined inFormula [A] supra, wherein SU_(s,j) is a parameter indicating a numberof software units required to run s-th software (s) in j-th physicalserver, as defined in Formula [A] supra, wherein L_(s) indicates arespective total number of available software license units for s-thsoftware (s), and wherein LCP_(s) is a parameter that has value zero (0)if the software license agreement is strictly followed and theadministrator does not permit additional number of software licenseunits than the current total number of available license units, and thathas value larger than zero (>0) if the administrator may authorizes touse more software licenses than the current total number of availablelicense units for s-th software (s)

In Formula [J], VM_(i,j) is the fourth binary variable that has valueone (1) if i-th VM will run on j-th physical server after workloadoptimization, and that has value zero (0) if i-th VM will not run onj-th physical server after workload optimization, as defined in Formula[B] supra, SVM_(i,s) is a seventh binary parameter that has value one(1) if i-th VM requires s-th software (s) and that has value zero (0) ifi-th VM does not require s-th software, and BigK indicates a constantvery larger than estimated number of software licenses required.

In step 4202, the WO maximizes a number of virtual machines that are notrelocated from a current physical server after the workloadoptimization, as the second phase of the two-phase VM topologycalculation. In the second phase, the WO searches for a minimum numberof relocations when taking the TC calculated from the first phase ofstep 4201 into account. Then the WO terminates the second phase of thetwo-phase VM topology calculation, and proceeds with step 430 of FIG.7A, supra.

The objective function of the second phase is:

Σ_(i,j)(CVM_(i,j)*VM_(i,j))  [L]

wherein CVM_(i,j) is the fifth binary variable that has value one (1) ifi-th VM currently runs on j-th physical server, and that has value zero(0) if i-th VM does not currently run on j-th physical server, asdefined in Formula [C] supra, and wherein VM_(i,j) is the fourth binaryvariable that has value one (1) if i-th VM will run on j-th physicalserver after workload optimization, and that has value zero (0) if i-thVM will not run on j-th physical server after workload optimization, asdefined in Formula [B] supra, subject to the same constraints from step4201 and another constraint on acceptable range of relocation cost.

Formula [M] is another constraint of the second phase to ensure that anew total cost does not significantly vary from the TC calculated in thefirst phase of step 4201 pursuant to Formula [A].

Σ_(s)(SC _(s)*Σ_(j)(SU _(s,j) *IS _(s,j)))+Σ_(j)(PC _(j) *B_(j))≦TC*(1+ACV)  [M]

wherein TC is the total cost calculated in step 4201 and wherein ACVindicates a predefined number representing acceptable cost variance overthe optimized total cost. Note that the left term of Formula [M] isdistinctive from TC calculated in the first phase by Formula [A] becausethe WO uses the new objective function represented by Formula [L] instep 4202 to minimize a number of relocations the new VM topology forworkload optimization.

FIG. 8 is a flowchart depicting reporting substeps performed in place ofstep 500 of FIG. 3 supra by the smart cloud workload balancer (SCWB) inaccordance with the embodiments of the present invention.

In step 510, the WO receives a request for report from the admin via theUser interface (UI). Then the WO proceeds with step 520.

In step 520, the WO configures a report based on the received requestfrom step 510. Then the WO proceeds with step 530.

In step 530, the WO extracts data items necessary for the configuredreport from objects database (ODB) and subsequently generated theconfigured report. Then the WO proceeds with step 540.

In step 540, the WO communicates the generated report comprisingextracted data items to the admin via the UI. Then the WO terminatesreporting and the SCWB proceeds with the WO performing another cycle ofoptimization.

FIG. 9 illustrates a computer system 90 used for optimizing workload bydynamically reallocating virtual machines of a cloud computing system,in accordance with the embodiments of the present invention.

The computer system 90 comprises a processor 91, an input device 92coupled to the processor 91, an output device 93 coupled to theprocessor 91, and memory devices 94 and 95 each coupled to the processor91. In this specification, the computer system 90 represents any type ofprogrammable data processing apparatus.

The input device 92 is utilized to receive input data 96 into thecomputer system 90. The input device 92 may be, inter alia, a keyboard,a mouse, a keypad, a touch screen, a scanner, a voice recognitiondevice, a sensor, a network interface card (NIC), a Voice/video overInternet Protocol (VOIP) adapter, a wireless adapter, a telephoneadapter, a dedicated circuit adapter, etc. The output device 93 isutilized to communicate results generated by the computer program code97 to a user of the computer system 90. The output device 93 may be,inter alia, a printer, a plotter, a computer screen, a magnetic tape, aremovable hard disk, a floppy disk, a NIC, a VOIP adapter, a wirelessadapter, a telephone adapter, a dedicated circuit adapter, an audioand/or visual signal generator, a light emitting diode (LED), etc.

Any of the components of the present invention can be deployed, managed,serviced, etc. by a service provider that offers to deploy or integratecomputing infrastructure with respect to a process for optimizingworkload by dynamically reallocating virtual machines of the cloudcomputing system of the present invention. Thus, the present inventiondiscloses a process for supporting computer infrastructure, comprisingintegrating, hosting, maintaining and deploying computer-readable codeinto a computing system (e.g., computing system 90), wherein the code incombination with the computing system is capable of performing a methodfor optimizing workload by dynamically reallocating virtual machines ofthe cloud computing system.

In another embodiment, the invention provides a method that performs theprocess steps of the invention on a subscription, advertising and/or feebasis. That is, a service provider, such as a Solution Integrator, canoffer to create, maintain, support, etc., a process for optimizingworkload by dynamically reallocating virtual machines of the cloudcomputing system of the present invention. In this case, the serviceprovider can create, maintain, support, etc. a computer infrastructurethat performs the process steps of the invention for one or morecustomers. In return, the service provider can receive payment from thecustomer(s) under a subscription and/or fee agreement, and/or theservice provider can receive payment from the sale of advertisingcontent to one or more third parties.

While FIG. 9 shows the computer system 90 as a particular configurationof hardware and software, any configuration of hardware and software, aswould be known to a person of ordinary skill in the art, may be utilizedfor the purposes stated supra in conjunction with the particularcomputer system 90 of FIG. 9. For example, the memory devices 94 and 95may be portions of a single memory device rather than separate memorydevices.

As will be appreciated by one skilled in the art, aspects of the presentinvention may be embodied as a system, method or computer programproduct. Accordingly, aspects of the present invention may take the formof an entirely hardware embodiment, an entirely software embodiment(including firmware, resident software, micro-code, etc.) or anembodiment combining software and hardware aspects that may allgenerally be referred to herein as a “circuit,” “module” or “system.”Furthermore, aspects of the present invention may take the form of acomputer program product embodied in one or more computer readablemedium(s) having computer readable program code embodied thereon.

Any combination of one or more computer readable medium(s) may beutilized. The computer readable medium may be a computer readable signalmedium or a computer readable storage medium. In this specification, theterm “memory device” 94, 95 represent a computer readable storagemedium. A computer readable storage medium may be, for example, but notlimited to, an electronic, magnetic, optical, electromagnetic infrared,or semiconductor system, apparatus, or device, or any suitablecombination of the foregoing. More specific examples (a non-exhaustivelist) of the computer readable storage medium would include thefollowing: an electrical connection having one or more wires, a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), an optical fiber, a portable compact disc read-onlymemory (CD-ROM), an optical storage device, a magnetic storage device,or any suitable combination of the foregoing. In the context of thisdocument, a computer readable storage medium may be any tangible mediumthat can contain, or store a program for use by or in connection with aninstruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, but not limited to,electro-magnetic, optical, or any suitable combination thereof. Acomputer readable signal medium may be any computer readable medium thatis not a computer readable storage medium and that can communicate,propagate, or transport a program for use by or in connection with aninstruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmittedusing any appropriate medium, including but not limited to wireless,wireline, optical fiber cable, radio frequency (RF), etc., or anysuitable combination of the foregoing.

Computer program code 97 for carrying out operations for aspects of thepresent invention may be written in any combination of one or moreprogramming languages, including an object oriented programming languagesuch as Java, Smalltalk, C++ or the like and conventional proceduralprogramming languages, such as the “C” programming language or similarprogramming languages. The computer program code 97 may execute entirelyon the user's computer, partly on the user's computer, as a stand-alonesoftware package, partly on the user's computer and partly on a remotecomputer or entirely on the remote computer or server. In the latterscenario, the remote computer may be connected to the user's computerthrough any type of network, including a local area network (LAN) or awide area network (WAN), or the connection may be made to an externalcomputer (for example, through the Internet using an Internet ServiceProvider).

Aspects of the present invention are described with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems) and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer program instructions. The term “computer program instructions”is interchangeable with the term “computer program code” 97 in thisspecification. These computer program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

These computer program instructions may also be stored in a computerreadable storage medium that can direct a computer, other programmabledata processing apparatus, or other devices to function in a particularmanner, such that the instructions stored in the computer readablestorage medium produce an article of manufacture including instructionswhich implement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer,other programmable data processing apparatus, or other devices to causea series of operational steps to be performed on the computer, otherprogrammable apparatus or other devices to produce a computerimplemented process such that the instructions which execute on thecomputer or other programmable apparatus provide processes forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof code, which comprises one or more executable instructions forimplementing the specified logical function(s). It should also be notedthat, in some alternative implementations, the functions noted in theblock may occur out of the order noted in the figures. For example, twoblocks shown in succession may, in fact, be executed substantiallyconcurrently, or the blocks may sometimes be executed in the reverseorder, depending upon the functionality involved. It will also be notedthat each block of the block diagrams and/or flowchart illustration, andcombinations of blocks in the block diagrams and/or flowchartillustration, can be implemented by special purpose hardware-basedsystems that perform the specified functions or acts, or combinations ofspecial purpose hardware and computer instructions.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present invention has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the invention. Theembodiment was chosen and described in order to best explain theprinciples of the invention and the practical application, and to enableothers of ordinary skill in the art to understand the invention forvarious embodiments with various modifications as are suited to theparticular use contemplated.

What is claimed is:
 1. A method, said method comprising: configuring, bya processor of a computer system using a smart cloud workload balancer(SCWB), a cloud computing system into an operative status by defining avirtual machine (VM) topology representing a respective virtual machineassignment for each physical server of the cloud computing system,wherein the cloud computing system services a workload of the cloudcomputing system by use of the VM topology, and wherein the cloudcomputing system comprises an objects database (ODB) storing systemconfiguration parameters comprising: a respective software cost persoftware application in one or more software license pools, a power costof the cloud computing system, and at least one virtual machine (VM);and determining, by the processor, that the cloud computing system doesnot perform optimally with respect to a total cost of the cloudcomputing system, wherein said total cost is a sum of the respectivesoftware cost and the power cost; and redistributing, by the processor,the workload of the cloud computing system pursuant to a new VM topologythat has a minimum total cost of the cloud computing system.
 2. Themethod of claim 1, said configuring comprising: identifying a virtualmachine and hardware manager (VMM) coupled to said each physical serverof the cloud computing system and subsequently storing the identifiedVMM in the ODB, wherein the SCWB controls operations of said eachphysical server via the VMM; defining business policies and subsequentlystoring the defined business policies in the ODB; defining andsubsequently storing, in the ODB, one or more physical serveravailability zones, one or more physical server restriction zones, andone or more physical server location pools, wherein the physical serveravailability zones define a first logical group of physical serverssharing one or more external physical components, wherein all physicalservers in a same physical server availability zone operate atomicallybut are not partially available, wherein said one or more externalphysical components are selected from the group consisting of a powerdistribution unit, a datacenter room, a rack, a network switch, anexternal storage, and combinations thereof, wherein the physical serverrestriction zones define a second logical group of physical serverswithin a specific physical server availability zone that dynamicallyrepresents a specific logical condition with respect to availablesoftware applications during a specific time period, and wherein thephysical server location pools define a third logical group of physicalservers having high communication requirements and are locally hosted bya same datacenter or a network, wherein the SCWB prevents a networkcongestion resulting from high data traffic between remote virtualmachines; creating and subsequently storing, in the ODB, the one or moresoftware license pools, and defining and subsequently storing, in theODB, respective available licenses per software application in thecreated software license pools; defining and subsequently storing, inthe ODB, the power cost of the cloud computing system; defining andsubsequently storing, in the ODB, the at least one virtual machine (VM),and one or more installed licenses per respective VM of the at least oneVM; and defining the VM topology based on the system configurationparameters stored in the ODB.
 3. The method of claim 1, saidredistributing comprising: retrieving data items from the ODB; computingthe new VM topology by use of retrieved data items; turning on a newgroup of physical servers comprised by the computed new VM topology;relocating virtual machines pursuant to the computed new VM topology onthe new group of physical servers; turning off a residual group ofphysical servers not included in the new group of physical serverspursuant to the computed new VM topology; and updating the retrieveddata items in the ODB corresponding to a new status of the cloudcomputing system pursuant to the computed new VM topology and the newgroup of physical servers.
 4. The method of claim 3, said computingcomprising: minimizing the total cost of the cloud computing systemrepresented by the sum of the respective software cost running on eachphysical server and the power cost for all running physical servers ofthe cloud computing system, subject to constraints that each virtualmachine (VM) is associated to only one physical server, that a number ofVM relocation is limited by a threshold, that each physical server has apredetermined amount of resources to run all VMs assigned for therespective physical server in the new VM topology, that a pair of twovirtual machines has either an affinity rule or an anti-affinity rule,wherein the resources are selected from the group consisting of memory,processing clock cycles, and input/output bandwidth, wherein theaffinity rule represents a first relationship between the pair of twovirtual machines that perform better when the pair run in a samephysical server, and wherein the anti-affinity rule represents a secondrelationship between the pair of two virtual machines that cannotperform in the same physical server, and that the amount of softwarelicense usage within the licensed limit; and maximizing a number ofvirtual machine relocations onto a same physical server as the VMtopology in the new VM topology, subject to the constraints of saidminimizing and also subject to other constraints that a relocation costfrom the VM topology to the new VM topology is within an acceptablevariance of the total cost.
 5. The method of claim 3, wherein saidcomputing is mathematically modeled by use of mathematical optimizationtechniques comprising quadratic programming (QP) and quadraticallyconstrained quadratic program (QCQP), wherein said computing isperformed by a QP and QCQP enabled solver coupled to the SCWB.
 6. Themethod of claim 1, said system configuration parameters stored by theODB further comprising: business policies, one or more physical serveravailability zones, one or more physical server restriction zones, oneor more physical server location pools, the one or more software licensepools, respective available licenses per software application in thesoftware license pools, and one or more installed licenses per VM. 7.The method of claim 1, said method further comprising: providing atleast one support service for at least one of creating, integrating,hosting, maintaining, and deploying computer-readable program code inthe computer system, said program code being executed by the processorto implement said configuring the cloud computing system, saiddetermining that the cloud computing system does not perform optimally,and said redistributing the workload.
 8. A computer program productcomprising a computer readable storage device having computer readableprogram code stored therein, said computer readable program codecontaining instructions which upon being executed by a processor of acomputer system, perform a method, said method comprising: configuring,by the processor using a smart cloud workload balancer (SCWB), a cloudcomputing system into an operative status by defining a virtual machine(VM) topology representing a respective virtual machine assignment foreach physical server of the cloud computing system, wherein the cloudcomputing system services a workload of the cloud computing system byuse of the VM topology, and wherein the cloud computing system comprisesan objects database (ODB) storing system configuration parameterscomprising: a respective software cost per software application in oneor more software license pools, a power cost of the cloud computingsystem, and at least one virtual machine (VM); and determining, by theprocessor, that the cloud computing system does not perform optimallywith respect to a total cost of the cloud computing system, wherein saidtotal cost is a sum of the respective software cost and the power cost;and redistributing, by the processor, the workload of the cloudcomputing system pursuant to a new VM topology that has a minimum totalcost of the cloud computing system.
 9. The computer program product ofclaim 8, said configuring comprising: identifying a virtual machine andhardware manager (VMM) coupled to said each physical server of the cloudcomputing system and subsequently storing the identified VMM in the ODB,wherein the SCWB controls operations of said each physical server viathe VMM; defining business policies and subsequently storing the definedbusiness policies in the ODB; defining and subsequently storing, in theODB, one or more physical server availability zones, one or morephysical server restriction zones, and one or more physical serverlocation pools, wherein the physical server availability zones define afirst logical group of physical servers sharing one or more externalphysical components, wherein all physical servers in a same physicalserver availability zone operate atomically but are not partiallyavailable, wherein said one or more external physical components areselected from the group consisting of a power distribution unit, adatacenter room, a rack, a network switch, an external storage, andcombinations thereof, wherein the physical server restriction zonesdefine a second logical group of physical servers within a specificphysical server availability zone that dynamically represents a specificlogical condition with respect to available software applications duringa specific time period, and wherein the physical server location poolsdefine a third logical group of physical servers having highcommunication requirements and are locally hosted by a same datacenteror a network, wherein the SCWB prevents a network congestion resultingfrom high data traffic between remote virtual machines; creating andsubsequently storing, in the ODB, the one or more software licensepools, and defining and subsequently storing, in the ODB, respectiveavailable licenses per software application in the created softwarelicense pools; defining and subsequently storing, in the ODB, the powercost of the cloud computing system; defining and subsequently storing,in the ODB, the at least one virtual machine (VM), and one or moreinstalled licenses per respective VM of the at least one VM; anddefining the VM topology based on the system configuration parametersstored in the ODB.
 10. The computer program product of claim 8, saidredistributing comprising: retrieving data items from the ODB; computingthe new VM topology by use of retrieved data items; turning on a newgroup of physical servers comprised by the computed new VM topology;relocating virtual machines pursuant to the computed new VM topology onthe new group of physical servers; turning off a residual group ofphysical servers not included in the new group of physical serverspursuant to the computed new VM topology; and updating the retrieveddata items in the ODB corresponding to a new status of the cloudcomputing system pursuant to the computed new VM topology and the newgroup of physical servers.
 11. The computer program product of claim 10,said computing comprising: minimizing the total cost of the cloudcomputing system represented by the sum of the respective software costrunning on each physical server and the power cost for all runningphysical servers of the cloud computing system, subject to constraintsthat each virtual machine (VM) is associated to only one physicalserver, that a number of VM relocation is limited by a threshold, thateach physical server has a predetermined amount of resources to run allVMs assigned for the respective physical server in the new VM topology,that a pair of two virtual machines has either an affinity rule or ananti-affinity rule, wherein the resources are selected from the groupconsisting of memory, processing clock cycles, and input/outputbandwidth, wherein the affinity rule represents a first relationshipbetween the pair of two virtual machines that perform better when thepair run in a same physical server, and wherein the anti-affinity rulerepresents a second relationship between the pair of two virtualmachines that cannot perform in the same physical server, and that theamount of software license usage within the licensed limit; andmaximizing a number of virtual machine relocations onto a same physicalserver as the VM topology in the new VM topology, subject to theconstraints of said minimizing and also subject to other constraintsthat a relocation cost from the VM topology to the new VM topology iswithin an acceptable variance of the total cost.
 12. The computerprogram product of claim 10, wherein said computing is mathematicallymodeled by use of mathematical optimization techniques comprisingquadratic programming (QP) and quadratically constrained quadraticprogram (QCQP), wherein said computing is performed by a QP and QCQPenabled solver coupled to the SCWB.
 13. The computer program product ofclaim 8, said system configuration parameters stored by the ODB furthercomprising: business policies, one or more physical server availabilityzones, one or more physical server restriction zones, one or morephysical server location pools, the one or more software license pools,respective available licenses per software application in the softwarelicense pools, and one or more installed licenses per VM.
 14. A computersystem comprising a processor, a memory coupled to the processor, and acomputer readable storage device coupled to the processor, said storagedevice containing program code which, upon being executed by theprocessor via the memory, implement a method, said method comprising:configuring, by the processor using a smart cloud workload balancer(SCWB), a cloud computing system into an operative status by defining avirtual machine (VM) topology representing a respective virtual machineassignment for each physical server of the cloud computing system,wherein the cloud computing system services a workload of the cloudcomputing system by use of the VM topology, and wherein the cloudcomputing system comprises an objects database (ODB) storing systemconfiguration parameters comprising: a respective software cost persoftware application in one or more software license pools, a power costof the cloud computing system, and at least one virtual machine (VM);and determining, by the processor, that the cloud computing system doesnot perform optimally with respect to a total cost of the cloudcomputing system, wherein said total cost is a sum of the respectivesoftware cost and the power cost; and redistributing, by the processor,the workload of the cloud computing system pursuant to a new VM topologythat has a minimum total cost of the cloud computing system.
 15. Thecomputer system of claim 14, said configuring comprising: identifying avirtual machine and hardware manager (VMM) coupled to said each physicalserver of the cloud computing system and subsequently storing theidentified VMM in the ODB, wherein the SCWB controls operations of saideach physical server via the VMM; defining business policies andsubsequently storing the defined business policies in the ODB; definingand subsequently storing, in the ODB, one or more physical serveravailability zones, one or more physical server restriction zones, andone or more physical server location pools, wherein the physical serveravailability zones define a first logical group of physical serverssharing one or more external physical components, wherein all physicalservers in a same physical server availability zone operate atomicallybut are not partially available, wherein said one or more externalphysical components are selected from the group consisting of a powerdistribution unit, a datacenter room, a rack, a network switch, anexternal storage, and combinations thereof, wherein the physical serverrestriction zones define a second logical group of physical serverswithin a specific physical server availability zone that dynamicallyrepresents a specific logical condition with respect to availablesoftware applications during a specific time period, and wherein thephysical server location pools define a third logical group of physicalservers having high communication requirements and are locally hosted bya same datacenter or a network, wherein the SCWB prevents a networkcongestion resulting from high data traffic between remote virtualmachines; creating and subsequently storing, in the ODB, the one or moresoftware license pools, and defining and subsequently storing, in theODB, respective available licenses per software application in thecreated software license pools; defining and subsequently storing, inthe ODB, the power cost of the cloud computing system; defining andsubsequently storing, in the ODB, the at least one virtual machine (VM),and one or more installed licenses per respective VM of the at least oneVM; and defining the VM topology based on the system configurationparameters stored in the ODB.
 16. The computer system of claim 14, saidredistributing comprising: retrieving data items from the ODB; computingthe new VM topology by use of retrieved data items; turning on a newgroup of physical servers comprised by the computed new VM topology;relocating virtual machines pursuant to the computed new VM topology onthe new group of physical servers; turning off a residual group ofphysical servers not included in the new group of physical serverspursuant to the computed new VM topology; and updating the retrieveddata items in the ODB corresponding to a new status of the cloudcomputing system pursuant to the computed new VM topology and the newgroup of physical servers.
 17. The computer system of claim 16, saidcomputing comprising: minimizing the total cost of the cloud computingsystem represented by the sum of the respective software cost running oneach physical server and the power cost for all running physical serversof the cloud computing system, subject to constraints that each virtualmachine (VM) is associated to only one physical server, that a number ofVM relocation is limited by a threshold, that each physical server has apredetermined amount of resources to run all VMs assigned for therespective physical server in the new VM topology, that a pair of twovirtual machines has either an affinity rule or an anti-affinity rule,wherein the resources are selected from the group consisting of memory,processing clock cycles, and input/output bandwidth, wherein theaffinity rule represents a first relationship between the pair of twovirtual machines that perform better when the pair run in a samephysical server, and wherein the anti-affinity rule represents a secondrelationship between the pair of two virtual machines that cannotperform in the same physical server, and that the amount of softwarelicense usage within the licensed limit; and maximizing a number ofvirtual machine relocations onto a same physical server as the VMtopology in the new VM topology, subject to the constraints of saidminimizing and also subject to other constraints that a relocation costfrom the VM topology to the new VM topology is within an acceptablevariance of the total cost.
 18. The computer system of claim 16, whereinsaid computing is mathematically modeled by use of mathematicaloptimization techniques comprising quadratic programming (QP) andquadratically constrained quadratic program (QCQP), wherein saidcomputing is performed by a QP and QCQP enabled solver coupled to theSCWB.
 19. The computer system of claim 14, said system configurationparameters stored by the ODB further comprising: business policies, oneor more physical server availability zones, one or more physical serverrestriction zones, one or more physical server location pools, the oneor more software license pools, respective available licenses persoftware application in the software license pools, and one or moreinstalled licenses per VM.